初识mybatis_03 一级缓存和二级缓存

package com.sunmap.dao;

import static org.junit.Assert.*;

import java.io.IOException;
import java.io.Reader;
import java.util.List;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.Test;

import com.sunmap.model.Article;
import com.sunmap.model.Person;

public class TestIPersonOperation_2 {

    @Test
    public void test() {
//        fail("Not yet implemented");
        try {
            Reader reader = Resources.getResourceAsReader("config/Configuration.xml");
            SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(reader);  

            SqlSession session = sqlSessionFactory.openSession();
            SqlSession session2 = sqlSessionFactory.openSession();
            
            String select = "com.sunmap.dao.IPersonOperation.selectPersonByID";
            String insert = "com.sunmap.dao.IPersonOperation.addPerson";
            
            
            /**
             * 测试mybatis一级缓存
             * */
//            Person p = session.selectOne(select, 19);
            /**如果session提交就说明对数据库做过增删改等操作，为了防止一级缓存读取到脏数据，所以一级缓存会清空*/
//            session.commit();
//            Person p2 = session.selectOne(select, 19);
//            Person p3 = session2.selectOne(select, 19);
            
//            System.out.println(p == p2);
//            System.out.println(p == p3);
            
            //一旦母库进行增删改，session一级缓存就会自动clean
//            Person p4 = new Person(21,"qwsdfds", 21);
//            session.update(insert, p4);
//            session.commit();
//            Person p5 = session.selectOne(select, 19);
//            Person p6 = session.selectOne(select, 19);
//            
//            System.out.println(p == p5);
//            System.out.println(p5 == p6);
            
            /**
             * 测试mybatis二级缓存
             * 
             * 二级缓存不建议使用，因为多表查询时会造成脏数据
             * */
            
            Person p = session.selectOne(select, 22);
            /**二级缓存是从cache中取得，只有提交才会进入到cache*/
            session.commit();
            Person p2 = session2.selectOne(select, 22);
            
            System.out.println(p == p2);
            
            
        } catch (IOException e) {
            e.printStackTrace();
        }
        
    }
    
}